This application relates to material handling apparatus of the general type in which a load is suspended from a pulley arrangement. In particular, the present invention relates to apparatus for measuring the magnitude of a load as it is handled by a material handling device. The principles of this invention are particularly applicable to material handling devices such as teeming cranes, container cranes, hook block arrangements and the like.
A known material handling apparatus which measures the magnitude of a suspended load is disclosed in British Pat. No. 1,105,493. The known material handling apparatus includes a block having a lifting yoke defining an opening for receiving a plate having intricately shaped slots defining a resiliently deflectable central portion. This central portion of the plate carries a load force which is measured by a transducer. The forming of the intricate slots in the plate contributes to the cost of making the material handling apparatus and must be accurately done. Many other devices are known which utilize strain sensing gages in a variety of different environments. Typical of such devices are tensiometers which measure the tension in yarn, a web, or the like, such as shown in U.S. Pat. No. 3,554,025.